Dynamic Kinetic Resolutions Catalyzed by a Planar-Chiral Derivative of DMAP:  Enantioselective Synthesis of Protected α-Amino Acids from Racemic Azlactones

Reactivity of Unsaturated 5(4H)-Oxazolones with Hg(II) Acetate: Synthesis of Methyl N-Benzoylamino-3-arylacrylates

“…In conclusion we observed that reaction of unsaturated 5(4H)-oxazolones with Hg(OAc) 2 in methanol did not lead to any metallated product. Instead mercury(II) acetate showed low…”

“…[18] However, the increased Lewis acid character of Hg compared to Pd may induce sometime a different reactivity behavior function of metal as it was already noticed in metallation of 1,5-bis(dimethylamino)naphthalene, when Hg(OAc) 2 and Pd(OAc) 2 gave different metallated products. 19 Another example is 3,4,5-trimethoxybenzaldehyde which does not react with Pd(OAc) 2 but it is easily mercuriated in the presence of mercury(II) acetate.…”

“…[2] The use of N-acylamino alkyl esters as the starting α-dehydroamino acid derivatives also enable the selective formation of the corresponding isoquinolines. [3] Some esters can be used as plant growth regulators, [4] while other acrylic acid derivatives have herbicidal activity [5] or are useful intermediates for the synthesis of the antiinflammatory agents.…”

Reaction of Substituted Furan-2-carboxaldehydes and Furo[b]pyrrole Type Aldehydes with Hippuric Acid

“…The most common method for their preparation is the Erlenmeyer-Plöchl reaction, a cyclodehydration-condensation of the appropriate aldehyde and hippuric acid in dry acetic anhydride catalysed by acetate anion (using sodium or calcium acetate as a support/catalyst) [11][12][13][14]. The formation of the carbon-carbon double bond usually leads to the creation of 1,3-oxazol-5(4H)-ones as a mixture of Z and E isomers; for example, furan-2-carboxaldehyde and thiophene-2-carboxaldehyde [11,12] and also substituted benzaldehydes [13] give oxazolones as such mixtures of two isomers.…”

Nonenzymatic, Enantioconvergent Dynamic Kinetic Resolution (DKR) of Racemic 2-(1H-Pyrrol-1-yl)alkanoic Acids as α-Amino Acid Equivalents

“…While a wide range of enzymatic DKRs 911 for α-amino acid derivatives has been disclosed as reliable methodologies, non-enzymatic DKRs have also emerged as promising approaches during the last decade. However, major examples of the successful nonenzymatic DKR of chiral α-amino acids have involved the catalytic ring-opening alcoholysis of cyclic precursors, such as racemic urethane-protected α-amino acid N-carboxyanhydrides (Deng 12 ) and racemic 2-phenylazlactones (Seebach, 13 Fu, 14 Berkessel, 1517 Connon, 18,19 Birman,20,21 etc.). Note that the DKR systems for racemic 2-phenylazlactones principally allowed production of N-benzoyl amino acids with high enantiopurities.…”